Premoistened sheets employed as wipers have become exceedingly popular for cleaning and/or treating adult and baby skin surfaces; in particular, the hands, face and perineal region. One reason for this popularity is that they can be used when access to washroom facilities is not readily available. For example, while traveling in automobiles; while engaging in sporting activities (e.g., tennis, golf, baseball, etc.), or while participating in camping, hiking, picnicking and related activities. For premoistened sheets to be effectively utilized in the above situations they must be packaged so that they can be transported conveniently without excessive evaporation or leakage of the moisturizing ingredients, and without becoming contaminated.
A flexible and pliable moisture-impervious package usable in the above situations is disclosed in U.S. patent application Ser. No. 859,860, filed on Dec. 12, 1977, now U.S. Pat. No. 4,131,195, and assigned to Scott Paper Company. This package includes a pocket portion in which the premoistened sheets are retained, and a flap portion joined to the pocket portion and adapted to overlie a dispensing opening extending through a flat wall of said pocket portion. In the commercial embodiment of the invention the product includes a separate moisture-impervious primary seal positioned over the dispensing opening, and the flap is adhesively fastened to the pocket portion in overlying relationship with the primary seal. In this condition the package can be stored for a long period of time without excessive loss of the moisturizing ingredients. When it is initially desired to dispense one or more sheets from the package, the primary seal is completely removed to expose the dispensing opening. Thereafter the flap portion is held in overlying relationship with the dispensing opening through a stripe of adhesive on the top wall of the pocket portion to provide the sealing function. This latter, or secondary seal is not nearly as effective in preventing moisture evaporation as the primary seal employed in the initially sold product; especially in severe conditions, such as exposure of the package to high temperatures (e.g., outdoor summer use). Therefore, a need is perceived to exist for an improved sealing arrangement, particularly after the package initially has been opened.
The '860 patent application also discloses other arrangements for establishing primary and secondary seals. However, these other arrangements either are no more effective in preventing moisture loss than the commercial embodiment, or were too difficult to form economically in a high speed mass production operation.